长白山北坡植被垂直带群落交错区的定量判定

以海拔梯度上的群落重要值和二元数据为指标，采用游动分割窗技术辨析了长白山北坡各植被带群落交错区的位置和宽度．结果表明，采用平方欧氏距离(SED)和Bray—Curtis距离函数(PD)计算的游动分割窗的峰值和峰宽有较好的重合性，其中基于灌木和草本物种重要值的平方欧氏距离更能准确地反映交错带植被的变异．依据游动分割窗的分析，判定阔叶红松林和暗针叶林的交错区为渐变类型，位于海拔1120m，宽度为200m，暗针叶林和岳桦交错区为急变类型，位于海拔1790m，宽度为50m，林线为急变类型，位于海拔2000m。宽度为40m．

Quantitative methodologies for ecotone determination on north slope of Changbai Mountains

Based on the community important values and present-absent data along elevation gradient on the north slope of Changbai Mountains and using moving split-window techniques, the width and location of vegetation ecotone were discussed in this article. The results showed that the methods of Bray-Curtis Percent Dissimilarity (PD) and Squared Euclidean Distance (SED) introduced in the analysis gave the similar results. Among the methods used in the moving split-window analysis, the SED method was the best in showing the variation of ecotone. According to the results of moving split-window techniques analysis, the ecotone between broad leaved-pine forest and dark conifer forest was gradual type, located in 1120 m a.s.l., spanned 200 m.; that between dark conifer forest and Betula ermanii forest was sharp type, located in 1790 m a.s.l., spanned 50 m; and the timberline was a sharp line, located in 2000 m, spanned 40 m.